Determination of a new podophyllotoxin derivative, TOP-53, and its metabolite in rat plasma and urine by high-performance liquid chromatography with electrochemical detection

A high-performance liquid chromatographic method was developed for the determination of a new podophyllotoxin derivative, TOP-53 (I), and TOP-53 glucuronide (II) as its major metabolite in rat plasma and urine. For the analysis of I, the sample was chromatographed on a reversed-phase C18 column with electrochemical detection after consecutive two-step liquid-liquid extractions. Compound II was determined as I after enzymatic hydrolysis of II. This method was validated sufficiently with respect to specificity, accuracy, and precision. The limits of quantitation for both I and II were 2 ng/ml in plasma and 10 ng/ml in urine. The method is thus useful for the pharmacokinetic study of I.     

Ruptured thymic cysts with mediastinal hemorrhage and hemothorax--a case report and reviews of the literature

We report a rare case with rupture of thymic cyst including mediastinal hemorrhage and hemothorax. A 68-year-old man was referred to our hospital for the treatment of right hemothorax. A chest roentgenogram following thoracentesis demonstrated a widened mediastinum. Chest computed tomograms revealed a large anterior mediastinal mass extending to the right pleural cavity and bilateral pleural effusion. Digital subtraction angiography showed a normal aorta and great vessels. A median stenotomy revealed a large encysted hematoma along the thymic cyst extending from the right anterior mediastinum into the right pleural cavity and ending with rupture. Pathological examination demonstrated that the largest thymic cyst was continued to the hematoma resulting from partial destruction of its epithelial lining. To our knowledge, only five cases including our's with ruptured thymic tumors were reported, and this is the first report of ruptured thymic cyst resulting in mediastinal hemorrhage and hemothorax.     

A hidden immunoglobulin G2 in patients with rheumatoid arthritis detected by nuclear magnetic resonance

OBJECTIVE: The ratios of immunoglobulin (Ig) G1 and IgG2 in patients with rheumatoid arthritis (RA) were examined by nuclear magnetic resonance (NMR) and the results were compared to data obtained by ELISA. METHODS: The IgG of 11 patients with RA were prepared with a DE-52 column and the specific signals for IgG1 and IgG2 were measured by NMR. The ratios of IgG1 and IgG2 were determined by the intensity of this signal. The samples were also measured by ELISA. RESULTS: The ratios of IgG2 in patients with RA measured by NMR were increased significantly compared to controls. However, there were no significant differences in the data determined by ELISA. Thus, a discrepancy exists in the analysis of IgG2 ratios between NMR and ELISA methods. CONCLUSION: There was a discrepancy in the IgG2 ratios of patients with RA between NMR and ELISA methods, and we attribute this to a conformational difference in IgG2 in patients with RA.     

Preoperative staging of endometrial carcinoma: diagnostic effect of T2-weighted fast spin-echo MR imaging

PURPOSE: To evaluate the usefulness of T2-weighted fast spin-echo magnetic resonance (MR) imaging with a 512 x 256 matrix for assessment of the preoperative stage of endometrial carcinoma. MATERIALS AND METHODS: Twenty-eight women with histopathologically proved endometrial carcinoma underwent preoperative T2-weighted fast spin-echo, dynamic T1-weighted fast spin-echo, and postcontrast T1-weighted spin-echo MR imaging with a phased-array surface coil. The uterine long-axis planes in each sequence were reviewed at separate sessions by three radiologists blinded to the histopathologic data. RESULTS: For the diagnosis of myometrial invasion, no statistically significant differences were found among T2-weighted imaging, dynamic imaging, and postcontrast T1-weighted imaging. For the diagnosis of deep myometrial invasion, T2-weighted and dynamic images showed higher specificity than postcontrast T1-weighted images (T2-weighted, 89%; dynamic, 88%; and postcontrast T1-weighted, 80%). For cervical invasion, T2-weighted and dynamic images showed larger areas under receiver operating characteristic curves than did postcontrast T1-weighted images (T2-weighted, 0.78; dynamic, 0.71; and postcontrast T1-weighted, 0.67). CONCLUSION: T2-weighted imaging is useful for identifying the stage of endometrial carcinoma.     

Microstructural evolution and mechanical property in dual two-phase intermetallic alloys composed of geometrically close-packed Ni3 X (X: Al and V) containing Nb

Dual two-phase intermetallic alloys composed of geometrically close-packed (GCP) structures of Ni₃Al (L1₂) and Ni₃V (D0₂₂) containing Nb were investigated in terms of microstructural evolution during low-temperature annealing (aging) and the related mechanical properties. The eutectoid region, i.e. the prior Al phase (Ni solid solution) is composed of the lamellar-like structure consisting of Ni₃Al (L1₂) and Ni₃V (D0₂₂) even at an early aging stage, and then coarsen with increasing aging time. The lamellar-like structure tend to align along direction and on {001} plane in the prior A1 phase (or the L1₂ phase). In a wide range of temperature, the dual two-phase intermetallic alloys showed high yield and tensile strength, and also reasonable tensile ductility, accompanied with ductile fracture mode. The observed mechanical properties were less sensitive to the microstructural evolution during low-temperature annealing (aging), meaning that the present dual two-phase intermetallic alloy is promising for a new type of high-temperature structural material.     

Discrete Conjugated Porphyrin Tapes with an Exceptionally Small Bandgap

An Ag^I‐promoted meso–meso coupling reaction has been extended to prepare discrete 100 nm long linear arrays of porphyrins. Oxidation of the resulting phenyl end‐capped meso–meso linked porphyrins using a combination of 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) and Sc^III(OTf)₃ directly produces fully π‐conjugated fused porphyrin arrays (porphyrin tapes) of 10 nm molecular size. This research news article presents their synthesis, X‐ray crystal structures, and optical and electronic properties. Among these, the extremely small highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) optical gaps that reach into the infrared region suggest many applications of these compounds in materials science.     

Displacement measurement of concrete bridges by the sampling Moiré method based on phase analysis of repeated pattern

Measuring accurate deformation distribution of large-scale structures inexpensively and efficiently is a crucial challenge of structural health monitoring. Phase-based imaging technique has great potential for accurate and robust multipoint displacement measurement in the field. In this study, the sampling Moiré method—one of the promising optical techniques—was applied to the displacement measurement of a concrete bridge for the high-speed railway in Japan. Using retroreflective Moiré markers, the two-dimensional in-plane displacements at multiple locations could be easily measured from recorded digital images at a distance of 20 m regardless of day and night. Results of the dynamic deflection obtained from the sampling Moiré method were in good agreement with those from a conventional laser Doppler vibrometer. The time series of two-dimensional displacement analyses when the outbound or inbound trains passed at the speed of 150 or 320 km/h through the bridge revealed that the points at the centre and the quarter of the bridge span demonstrated complex deformation behaviour showing elliptical rotation. The effects of random noise of the recorded image were quantitatively investigated, and the air fluctuation was discussed from the field experiments. We proved that measurements using the sampling Moiré method could be more stable at night than daytime.     

Influence of N and Fe on α-Ti precipitation in the in situ TiC–titanium alloy composites

High strength with high ductility can be achieved in the titanium alloys by using metal precipitated ceramic particle as reinforcement. In this work, α + β or β-Ti alloy composites were prepared with α-Ti precipitated TiC particles. A series of Ti–Fe–C–N alloys were prepared and a constitutional diagram was constructed as a function of N and Fe contents. Two criteria were identified for the formation of α-Ti precipitation. One is the existence of Ti₂C phase and the other is the presence of α-Ti phase in the matrix. The mechanism of α-Ti formation from the Ti₂C phase is discussed.     

煅烧炉用喷射耐火料的近期发展趋向

开发了一种干式喷射隔热材料,其热导率与隔热板一样低.它正取代普通的隔热板,因它的安装方便,工作环境较好.另外,我们已开发了新的湿式喷射料体系,它效率高,工作环境好.